This invention relates to electronic synthesis of waveforms and more particularly, to the synthesis of complex waveforms that are the sum of one or more discrete sinusoid components.
In prior art synthesis, a contribution is added to one or more cell frequencies of the frequency spectrum of the desired waveform. Segments of the desired waveform in the time domain are then obtained by performing a discrete inverse Fourier transform on the sum on the cell frequencies. The desired waveform is obtained by concatenation of the resulting segments. However, unless the frequencies of the desired waveform equal or are very close to the discrete cell frequencies, successive segments of the waveform will not be phase matched at the segment boundaries and excessive modulation of the resulting waveform will occur. Only by adding contributions to a prohibitive number of spectral cells for each desired sinusoid component can this modulation be avoided.